Pneumatic stopper for gas-mains



Feb. 6, 1934. w, W` GARDNER 1,946,138

PNEUMATIC STOPPER FOR GAS MAINS Filed April l5, 1932 ar, mim

Patented Feb. 6, 1934 UNTED STATES PATENT FFIC 3 Claims.

My invention relates to an improved pneumatic stopper for use in given sections of gas-mains for checking the flow of gas therethrough as may be required preparatory to new installations of gasmains, to making alterations in existing gasmains, and to kindred operations of Whatever character requiring the temporary checking of the flow of gas through the mains, the object being to produce, for the purposes indicated, a safe, simple and compact, quick and convenient device for inserting a bag into a gas-main without the escape therefrom of sufficient gas to overcome or even inconvenience the workmen employed. More particularly, my invention relates to an improvement upon the pneumatic gas-main stopper forming the subject-matter of my Patent No. 1,860,855, granted May 3l, 1932.

With these ends in View, my invention consists in a pneumatic gas-main stopper having certain 20 detailsiof construction as will be hereinafter described and pointed out inthe claims. In the accompanying drawing:

Fig. l is a View in elevation of a pneumatic gasmain stopper embodying my invention; Fig. 2 is an enlarged broken sectional view thereof with the bag retracted into its housing; Fig. 3 is a similar view showing the stopper as applied to a gas-main and the bag ejected thereinto and fully expanded therein to form a complete stop against the flow of gas therethrough; Fig. 4 is a sectional view on the line 4-4 of Fig. 1; and

Fig. 5 is a sectional view on the line 5 5 of Fig. 2. 35 In carrying out my invention as herein shown.

I employ a tubular bag-housing large enough in diameter to permit the bag when deflated to be completely housed therein. The deatable bag, as shown, consists of a rubber body 11 having a tubular neck 12 which is made thicker and, therefore, stronger than the said body which is enclosed in a protecting envelope 13 of canvas or similar material, also having a complementary tubular neck 14 to enclose the neck 12 of the body 11. The neck 12 of the body and the neck 14 of its envelope receive a nipple 15 having its inner end enlarged to form a head 16 which tends to prevent the neck 12 and its envelope 13 from being drawn away from the nipple upon which they are clamped by a metal band 17 having perforated ears 18 receiving a clamping bolt 19. In this manner the nipple 15 is permanently mounted in the neck 12 of the bag. The outer end of the said nipple is :formed with a socket 20 internally threaded to adapt it to be screwed over the threaded inner end of a tubular combined plunger and air-tube 21, which is provided as shown near its inner end with a piston packing consisting of a pair of corresponding washers 22 and 23 separated by a spacing-washer 24. A nut 25 upon the threaded inner end of the plunger 21 holds the washers against upward movement thereon, while they are compressed together by the end of a threaded socket 20 formed at the outer end of the nipple 15, a washer 26 being interposed between the end of the socket and the washer 23. When the nipple is screwed upon the threaded end of the plunger, the Washers are compressed and held.

It will be understood that the bags for use in the device are supplied with nipples perma nently installed in them, so that when it is desired to replace a bag for any reason, it is only necessary to unscrew the nipple from the inner end of the plunger 21 and screw on another bag.

At its upper end the housing 10 is provided with a bearing-cap 27 through which the plunger 10 is drawn back and forth. The cap has a lubricating-hole 27 closed by a screw 27h. At its projecting upper end the plunger is threaded for the reception of a combined head 'and handle, comprising a body 28 having oppositely-extending integral handles 29. The said body 28 is formed with two bosses 30 and 31 located opposite each other on a line at a right angle to the axes of the handles 29, and having passages 32 which open into the outer end of the central passage or bore of the tubular plunger 21. The boss 30 receives the stem 33 of a pressure-gauge 34 of any suitable construction, while the boss 31 receives the stem 35 of a nipple 36 over which an air-feed tube (not shown) is sleeved, this nipple containing an air-valve having a projecting stem 37 of any suitable construction.

The head 28 is also provided with an air-deiating passage 38 normally closed by a removable threaded donating-plug 39. Air under pressure entering through the nipple 36, passes downward through the plunger into the bag, the pressure developed in the bag at any given moment being registered by the gauge 34. For the speedy deiiation of the bag, the plug 39 is removed. The bag is normally housed entirely within the housing 10 in which it is fully protected against injury in the transportation and handling of the stopper.

In using the device, a hole 40 is tapped in the gas-main 41 at the desired point therein, and the housing quickly screwed into it. The housing having been iirmly mounted in the tapping as described, the plunger 21 is forced downward in the housing 1G until stopped by the engagement with the upper end thereof ci a collar 42 adjustably mounted upon the plunger so as to properly limit the movement thereof downward in the housing. At this time, the bag is ejected out of the housing into the gas-main without any abrasion of the bag, since its full course out or" the housing into the main is protected, When the bag has been injected into the main as described, air under pressure is supplied through the nipple 36 until the bag is inflated and fully fills the main, as shown in Fig. 3, so as to constitute a stop for the gas owing through the same.

It will be understood that the pressure of air introduced into the bag must be suiicient to expand it against the pressure of gas in the main. After the bag has been fully expanded, it is sealed by the action of the valve in the nipple 36 or in any other convenient manner. When the bag is introduced into the main, it be displaced one way or the other out oi center, as shown in Fig. 3, according to the direction in which the gas is flowing through the main and dependent upon the pressure of the gas. After the operation, whatever its character, has been finished, the deflating-plug 39 is removed from the head 28, when the pressure of the gas in the main will speedily deiiate the bag. The housing is now unscrewed from the main and the stopper as a unit removed therefrom, the deflated bag passing readily through the tapping in the main, which is then plugged, with the escape of a minimum amount of gas, or, ir" preferred, the bag may be retracted by the plunger 21 into the housing 10 before the same is unscrewed from the tapping in the gas-main. Generally, more than one of these Stoppers will be used at the same time, depending upon the character of the work being done.

My improved device is primarily designed for use as a stopper for gas-mains and may be adapted to high, low or intermediate pressures of gas. It may also be used to advantage in water-mains, and I would have it so understood.

I claim:

1. A portable pneumatic stopper for gas-mains having a tubular bag-housing threaded at its inner end for direct application to a tapping in a gas-main, a combined plunger and air-tube mounted in the said housing and having its lower end threaded, a piston-packing mounted upon the said combined plunger and air-tube, and a defiatable bag having a neck, and a nipple permanently mounted in the said neck and provided at its outer end with a threaded socket for being readily detachably applied to the threaded inner end of the combined plunger and tube at a point below the said piston-packing.

2. A portable pneumatic stopper for gas-mains having a tubular bag-housing threaded at its inner end for direct application to a tapping in a gas-main, a combined plunger and air-tube mounted in the said housing and having its lower end threaded, piston-packing mounted upon said threaded lower end of the combined plunger and air-tube, a deflatable bag having a neck, and a nipple permanently mounted in the said neck, said nipple having an outer end provided with a threaded socket for being readily detachably applied upon said threaded lower end of the combined plunger and air-tube to readily detachably hold said piston-packing in place and readily detachably connect said deflatable bag with said combined plunger and air-tube.

3. A portable pneumatic stopper for gas-mains having a tubular bag-housing threaded at its inner end for direct application to a "tapping in a gas-main, a combined plunger and air-tube mounted in the said housing and having its lower end threaded, pistonand air-tube-packing mounted upon said threaded lower end of the combined plunger and air-tube, a deflatable bag having a neck, and a nipple permanently mounted in the said neck, said nipple having an outer end provided with a threaded socket for being readily detachably applied upon said threaded lower end of the combined plunger and air-tube to readily detachably hold said pistonand airtube-packing in place and readily detachably connect said deflatable bag with said combined plunger and air-tube.

WILLIS VJ' GARDNER. 

